// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/formats/common/offset_byte_queue.h"

#include <stdint.h>
#include <string.h>

#include <memory>

#include "testing/gtest/include/gtest/gtest.h"

namespace media {

class OffsetByteQueueTest : public testing::Test {
public:
    void SetUp() override
    {
        uint8_t buf[256];
        for (int i = 0; i < 256; i++) {
            buf[i] = i;
        }
        queue_.reset(new OffsetByteQueue);
        queue_->Push(buf, sizeof(buf));
        queue_->Push(buf, sizeof(buf));
        queue_->Pop(384);

        // Queue will start with 128 bytes of data and an offset of 384 bytes.
        // These values are used throughout the test.
    }

protected:
    std::unique_ptr<OffsetByteQueue> queue_;
};

TEST_F(OffsetByteQueueTest, SetUp)
{
    EXPECT_EQ(384, queue_->head());
    EXPECT_EQ(512, queue_->tail());

    const uint8_t* buf;
    int size;

    queue_->Peek(&buf, &size);
    EXPECT_EQ(128, size);
    EXPECT_EQ(128, buf[0]);
    EXPECT_EQ(255, buf[size - 1]);
}

TEST_F(OffsetByteQueueTest, PeekAt)
{
    const uint8_t* buf;
    int size;

    queue_->PeekAt(400, &buf, &size);
    EXPECT_EQ(queue_->tail() - 400, size);
    EXPECT_EQ(400 - 256, buf[0]);

    queue_->PeekAt(512, &buf, &size);
    EXPECT_EQ(NULL, buf);
    EXPECT_EQ(0, size);
}

TEST_F(OffsetByteQueueTest, Trim)
{
    EXPECT_TRUE(queue_->Trim(128));
    EXPECT_TRUE(queue_->Trim(384));
    EXPECT_EQ(384, queue_->head());
    EXPECT_EQ(512, queue_->tail());

    EXPECT_TRUE(queue_->Trim(400));
    EXPECT_EQ(400, queue_->head());
    EXPECT_EQ(512, queue_->tail());

    const uint8_t* buf;
    int size;
    queue_->PeekAt(400, &buf, &size);
    EXPECT_EQ(queue_->tail() - 400, size);
    EXPECT_EQ(400 - 256, buf[0]);

    // Trimming to the exact end of the buffer should return 'true'. This
    // accomodates EOS cases.
    EXPECT_TRUE(queue_->Trim(512));
    EXPECT_EQ(512, queue_->head());
    queue_->Peek(&buf, &size);
    EXPECT_EQ(NULL, buf);

    // Trimming past the end of the buffer should return 'false'; we haven't seen
    // the preceeding bytes.
    EXPECT_FALSE(queue_->Trim(513));

    // However, doing that shouldn't affect the EOS case. Only adding new data
    // should alter this behavior.
    EXPECT_TRUE(queue_->Trim(512));
}

} // namespace media
